The present invention relates to polyisocyanate based polymers prepared from formulations including non-silicone surfactants. The present invention particularly relates to polyurethane, polyisocyanurate and polyurea foams prepared from formulations including non-silicone surfactants.
Polyisocyanate based polymers are known to be useful. Methylene diphenyldiisocyanate (MDI) and toluene diisocyanate (TDI) are useful monomeric polyisocyanates. Polymeric isocyanates, particularly polymeric methylene diphenyl diisocyanate (sometimes also referred to as polymethylene polyphenyl polyisocyanate, hereinafter PMDI) are very useful polymeric intermediate materials. They are used primarily as components in thermoset and thermoplastic polymer elastomers, and rigid and flexible polyurethane, polyurea and polyisocyanurate foams. Polyisocyanate based elastomers are used in applications such as reaction injection molded automobile body parts, injection molded skateboard wheels, and extruded disposable diaper components.
Polymeric isocyanates are particularly valued for the excellent insulating properties of foams prepared therewith. These insulating foams may be found in applications ranging from home construction to ice chests and refrigerators and even to industrial applications such as pipe and vessel insulation. Such foams are typically rigid.
Flexible polyurethane foams are used in a wide variety of applications, such as bedding, furniture cushioning, automobile seating, headrests, dashboards, packaging, toys and the like. These foams are generally prepared by reacting a nominally di- or trifunctional, high equivalent weight polyol with a polyisocyanate, in the presence of a blowing agent and sometimes also in the presence of a minor amount of a crosslinker.
These foams are commonly separated into two types, according to their method of manufacture. Molded foams are prepared by reacting the polyurethane-forming components in a closed mold to produce foams having a predetermined shape. In contrast, slab-stock foams are prepared by permitting the foam components to freely rise against their own weight.
It is known in the art of preparing polymer foams wherein one of the reactants is a polyisocyanate to use surfactants to compatibilize the reaction mixture and to stabilize forming foams. Often these surfactants are silicone based. For example, U.S. Pat. No. 5,064,872 to Monstrey, et al., discloses preparing polyisocyanurate foams from formulations including a polyalkylsiloxane polyether copolymer foam stabilizer. U.S. Pat. Nos. 4,097,406 and 4,172,186 to Scott, et al., discloses preparing polyurethane foams from formulations including the reaction product of reacting a silicon tetrahalide with water and an alcohol followed by transesterification with a polyether polyol.
While using silicone surfactants as stabilizers in polymer formulations is very common, it is not necessarily always the best solution in every application. One disadvantage of silicone surfactants is their cost. Silicone surfactant materials are often one of the most expensive components in a polymer formulation. Therefore, it would be desirable in the art of preparing polymers from formulations including polyisocyanates to include a non-silicone surfactant in the formulation which is significantly lower in cost than silicone surfactants imparting about the same properties to the foams produced therewith.